ORGANIC MOLECULES (BIOMOLECULES) Tellez Carmona José Manuel 1 ORGANIC MOLECULES Organic molecules are those that: 1) formed by the actions of living things; and/or 2) have a carbon backbone. Methane (CH4) is an example of this. • If we remove the H from one of the methane units below, and begin linking them up, while removing other H units, we begin to form an organic molecule. • (NOTE: Not all methane is organically derived, methane is a major component of the atmosphere of Jupiter, which we think is devoid of life). • When two methanes are combined, the resultant molecule is Ethane, which has a chemical formula C2H6. Molecules made up of H and C are known as hydrocarbons. Tellez Carmona José Manuel 2 FUNCTIONAL GROUPS Scientists eventually realized that specific chemical properties were a result of the presence of particular functional groups. F unctional groups are clusters of atoms with characteristic structure and functions. Polar molecules (with +/- charges) are attracted to water molecules and are hydrophilic. Nonpolar molecules are repelled by water and do not dissolve in water; are hydrophobic. Hydrocarbon is hydrophobic except when it has an attached ionized functional group such as carboxyl (acid) (COOH), then molecule is hydrophilic. Tellez Carmona José Manuel 3 Each organic molecule group has small molecules (monomers) Monomers can be joined together to form polymers that are the large macromolecules made of three to millions of monomer Tellez Carmona José Manuel that are linked to form a larger organic molecule (macromolecule). subunits. 4 Macromolecules are constructed by covalently bonding monomers by condensation reactions where water is removed from functional groups on the monomers. polymers). Condensation involves a dehydration synthesis because a water is removed (dehydration) and a bond is made (synthesis). When two monomers join, a hydroxyl (OH) group is removed from one monomer and a Tellez Carmona José Manuel Cellular enzymes carry out condensation (and the reversal of the reaction, hydrolysis of hydrogen (H) is removed from the other. • This produces the water given off during a condensation reaction. Hydrolysis (hydration) reactions break down polymers in reverse of condensation; a hydroxyl (OH) group from water attaches to one monomer and hydrogen (H) attaches to the other. 5 MAIN BIOMOLECULES Tellez Carmona José Manuel 6 THE MOST IMPORTANT MACROMOLECULES IN BIOLOGY… There are four classes of macromolecules (polysaccharides, variety of functions in cells. Tellez Carmona José Manuel triglycerides, polypeptides, nucleic acids). These classes perform a 7 BIOMOLECULES SUMMARY… LAS PRINCIPALES MOLÉCULAS BIOLÓGICAS Principales subtipos (subunidades en paréntesis) Ejemplo Función Carbohidrato: normalmente contiene carbono, oxígeno e hidrógeno y tiene la formula aproximada (CH2O)n Monosacárido: azúcar simple Disacárido: dos monosacáridos enlazados Polisacárido: muchos monosacáridos (normalmente glucosa) enlazados Glucosa Sacarosa Almidón Glucógeno Celulosa Importante fuente de energía para las células; subunidad con la que se hacen casi todos los polisacáridos Principal azúcar transportado dentro del cuerpo de las plantas terrestres Almacén de energía en plantas Almacén de energía en animales Material estructural de plantas Lípido: Contiene una proporción elevada de carbono e hidrógeno; suele ser no polar e insoluble en agua Tliglicerido: tres ácidos grasos unidos a glicerol Cera: número variable de ácidos grasos unidos a un alcohol de cadena larga Fosfolípido: grupo fosfato polar y dos ácidos grasos unidos a glicerol Esteroide: 4 anillos fusionados de átomos de carbono, con grupos funcionales unidos Aceite, grasa Ceras en la cutícula de las plantas Fosfatidilcolina Colesterol Almacén de energía en animales y algunas plantas Cubierta impermeable de las hojas y tallos de plantas terrestres Componente común de las membranas de las células Componente común de las membranas de las células eucarióticas; precursor de otros esteroides como testosterona, sales biliares Tellez Carmona José Manuel Clase de molécula 8 BIOMOLECULES… LAS PRINCIPALES MOLÉCULAS BIOLÓGICAS Clase de molécula Proteína: Cadenas de aminoácidos; contiene carbono, hidrógeno, oxígeno, nitrógeno y azufre Ejemplo Función Queratina Seda Hemoglobina Ácidos nucleicos de cadena larga Nucleótidos individuales Acido desoxirribonucleico (ADN) Acido Ribonucleico (ARN) Trifosfato de adenosina (ATP) Monofosfato de adenosina cíclico (AMP cíclico) Proteína helicoidal, principal componente del pelo Proteína producida por polillas y arañas Proteína globular formada por 4 subunidades peptídicas; transporta oxígeno en la sangre de los vertebrados Material genético de todas las células vivas Material genético de algunos virus; en las células vivas es indispensable para transferir la información genética del ADN a las proteínas Principal molécula portadora de energía a corto plazo en las células Mensajero intracelular Tellez Carmona José Manuel Acido nucleico: Formado por subunidades llamadas nucleótidos; puede ser uno solo o una cadena larga de nucleótidos. Principales subtipos (subunidades en paréntesis) (aminoácidos) 9 Sugars… CARBOHYDRATES Tellez Carmona José Manuel 10 CARBOHYDRATES Carbohydrates have the general formula [CH2O]n where n is a number between 3 and 6. Carbohydrates function in short-term energy Sugars are structurally the simplest carbohydrates. storage (such as sugar); as intermediate-term energy They are the structural unit which makes storage (starch for plants and glycogen for animals); up the other types of carbohydrates. and as structural components in cells (cellulose in the Monosaccharides are single (mono=one) cell walls of plants and many protists), and chitin in sugars. Important monosaccharides include the exoskeleton of insects and other arthropods. ribose (C5H10O5), glucose (C6H12O6), and fructose (same formula but different structure than glucose). Tellez Carmona José Manuel 11 ALFA AND BETA GLUCOSE Tellez Carmona José Manuel 12 DISACCHARIDES are formed when two monosaccharides are chemically bonded together. and fructose. Lactose, milk sugar, is a disaccharide composed of glucose and the monosaccharide galactose. Tellez Carmona José Manuel Sucrose, a common plant disaccharide is composed of the monosaccharides glucose The maltose that flavors a malted milkshake (and other items) is also a disaccharide made of two glose molecules bonded together 13 Tellez Carmona José Manuel 14 DISACCHARIDES : "DEHYDRATION SYNTHESIS ". When two monosaccharides are joined together they form a "disaccharide". This linking of two sugars involves the removal of a molecule of H2O (water) and is therefore called a "dehydration linkage". The reaction is called "dehydration synthesis". e.g. Glucose + Glucose = Maltose Tellez Carmona José Manuel 15 Polysaccharides • These are long chains of monosaccharides linked together by dehydration linkages. Tellez Carmona José Manuel 16 POLY SACCHARIDES are large molecules composed of individual monosaccharide units. A common plant polysaccharide is starch which is made up of many glucoses (in a polypeptide these are referred Two forms of polysaccharide, amylose and amylopectin makeup what we commonly call starch. The formation of the ester bond by condensation (the removal of water from a molecule) Tellez Carmona José Manuel to as glucans). allows the linking of monosaccharides into disaccharides and polysaccharides. Glycogen (see Figure 12) is an animal storage product that accumulates in the vertebrate liver. 17 CELLULOSE (HOMOPOLY SACARID ) is a polysaccharide found in plant cell walls. • Cellulose forms the fibrous part of the plant cell wall. • In terms of human diets, cellulose is indigestible, and thus forms an important, easily obtained part of dietary fiber. As compared to starch and glycogen, which are each made up of mixtures of a and b glucoses, cellulose (and the animal structural polysaccharide chitin) are made up of only b glucoses. Tellez Carmona José Manuel 18 HETEROPOLYSACARIDS Chitin: is an important structural material in the outer coverings of insects, crabs, and lobsters. In chitin the basic subunit is not glucose (but N-acetyl-D-glucoseamine) carbonate. Tellez Carmona José Manuel in 1-4 linkages. These polymers are made very hard when impregnated with calcium 19 Fatty acids LIPIDS Tellez Carmona José Manuel 20 are involved mainly with long-term energy storage. LIPIDS Fatty acids can be saturated (meaning They are generally insoluble in polar substances such as water. they have as many hydrogens bonded to their carbons as possible) or unsaturated (with one or more double bonds connecting their Secondary functions of lipids include carbons, hence fewer hydrogens). structural components (as in the case of phospholipids that are the major building block in cell membranes) and "messengers" (hormones) that play roles in A fat is solid at room temperature, while an oil is a liquid under the same conditions. • communications within and between cells. Lipids are composed of three fatty acids (usually) covalently bonded to a 3-carbon glycerol. The fatty acids are composed of CH2 units, and are hydrophobic/not water • The fatty acids in oils are mostly unsaturated, while those in fats are mostly saturated. Lipids include the compounds commonly known as fats, oils, and waxes. We will look at three important classes of lipids. soluble. Tellez Carmona José Manuel 21 THE TRIGLYCERIDES Both fats and oils are "triglycerides". These molecules are made up of 3 long chain "fatty acids" attached to a 3 carbon molecule called "glycerol". The carboxyl and the fatty acids are attached to the -OH groups of the Glycerol via a "dehydration synthesis" reaction to yield an "ester" bond. Function: storage of energy "fat" in animals, and "oils" in plants. Tellez Carmona José Manuel 22 Animals convert excess sugars (beyond their glycogen storage capacities) into fats. Most plants store excess sugars as starch, although some seeds and fruits have energy stored as oils (e.g. corn oil, peanut oil, palm oil, canola oil, and sunflower oil). Fats yield 9.3 Kcal/gm, while carbohydrates yield 3.79 Kcal/gm. Fats thus store six times as much energy as Fats and oils function in long-term energy storage. glycogen. Tellez Carmona José Manuel 23 SATURATED AND UNSATURATED FATTY Saturated Fatty Acid: These are fatty acids which ACIDS Unsaturated Fatty Acid: These are fatty acids which contain carbon-to-carbon contain the maximum possible number of hydrogen "double" bonds. Therefore since a carbon atom can have only 4 covalent bonds, atoms. That is each carbon in the chain has two there is one less bond available for hydrogen, therefore there is one less hydrogen atoms attached to it. It is "saturated" with hydrogen. (The carbons are not "saturated" with hydrogen atoms.) hydrogen atoms. Tellez Carmona José Manuel 24 CLASS ACTIVITY Directions. 1. Answer the next questions: 1. Work in teams of three 2. Read the next 6 slides 3. To generate a mindmap over all the 6 slides in a papersheet 4. Generate a table showing differences between cis and trans Tellez Carmona José Maneeuel 1. What are satured and unsatured fatty acids? 2. Are both of them good or bad for your healthy? 3. What is an eicosanoid? 4. What is hydrogenation? What is used for? 5. What are Cis and trans configuration? 6. Which is best for your health of both of them? 7. What is the meaning of LDL and HDL and what is used for each one of them? 8. Why is trans bad for your brain and heart? 25 FA T T Y A C I D C O N F I G U R A T I O N S T R A N S FA T S : W H A T ' S U P W I T H THAT? Configurational isomers What are Trans Fats? Cis configuration (oleic Acid) Double bonds bind carbon atoms tightly and prevent rotation of the carbon atoms along the bond axis. This gives rise to configurational isomers which Trans configuration (Elaidic are arrangements of atoms that can acid) only be changed by breaking the bonds. Cis means "on the same side" and Trans means "across" or "on Tellez Carmona José Manuel the other side" 26 HYDROGENATION AND PARTIAL HYDROGENATION? Unsaturated fats exposed to air oxidize to Hydrogen is incorporated into the fatty create compounds that have rancid, stale, or acid molecules and they become saturated unpleasant odors or flavors. with hydrogen. Oleic acid (C18:1) and linoleic acid (C18:2) are both converted to Hydrogenation is a commercial chemical stearic acid (C18:0) when fully saturated. process to add more hydrogen to natural unsaturated fats to decrease the number of double bonds and retard or eliminate the potential for rancidity. The liquid vegetable oil becomes a solid saturated fat (shortening with a large percentage of tristearin). Unsaturated oils, such as soybean oil, which contain unsaturated fatty acids like oleic and By comparison, animal fats seldom have linoleic acid, are heated with metal catalysts in the more than 70% saturated fatty acid radicals. presence of pressurized hydrogen gas. In the table above, for example, lard has 54% unsaturated fatty acid radicals. Tellez Carmona José Manuel 27 METABOLISM OF FATS -WHY ARE TRANS FATS BAD? Metabolism of natural 20-carbon polyunsaturated fatty acids like arachidonic acid results in the biosynthesis of mediators with Metabolism of natural C20 Cis fatty acids produces powerful eicosanoids. potent physiological effects such as prostaglandins, prostacyclins, thromboxanes, Although low levels of trans-vaccenic acid occur naturally in some animal food products, partially hydrogenated oils contain a large proportion of diverse These substances are known collectively as trans fatty acids. eicosanoids because they contain 20 carbon When large amounts of Trans fatty acids are atoms (Greek eikosi = 20). incorporated into the cells, the cell membranes and leucotrienes, and lipoxins. other cellular structures become malformed and do not function properly. However, polyunsaturated trans fatty acids cannot be used to produce useful mediators because the molecules have unnatural shapes that are not recognized by enzymes such as cyclooxygenase and lipoxygenase. Tellez Carmona José Manuel 28 TRANS IS BAD FOR YOUR HEART… Trans fats are bad for your heart. Dietary trans fats raise the level of low-density lipoproteins (LDL or "bad cholesterol") increasing the risk of coronary heart disease. Trans fats also reduce high-density lipoproteins (HDL or "good cholesterol"), and raise levels of triglycerides in the blood. Tellez Carmona José Manuel Both of these conditions are associated with insulin resistance which is linked to diabetes, hypertension, and cardiovascular disease. Harvard University researchers have reported that people who ate partially hydrogenated oils, which are high in Trans fats, had nearly twice the risk of heart attacks compared with those who did not consume hydrogenated oils. B ecause of the overwhelming scientific evidence linking Trans fats to cardiovascular diseases, the Food and Drug Administration will require all food labels to disclose the amount of Trans fat per serving, starting in 2006. 29 TRANS IS BAD FOR YOUR BRAIN… Trans fats are bad for your brain. Trans fats also have a detrimental effect on the brain and nervous system. Neural tissue consists mainly of lipids and fats. Myelin, the protective sheath that covers communicating neurons, is composed of 30% protein and 70% fat. Oleic acid and DHA are two of the principal fatty acids in myelin. Studies show that trans fatty acids in the diet get incorporated into brain cell membranes, including the myelin sheath that insulates Trans fatty acid molecules alter the ability of neurons to communicate and may cause neural degeneration and diminished mental performance. Neurodegenerative disorders such as multiple sclerosis (MS), Parkinson's Disease, and Alzheimer's Disease appear to exhibit membrane loss of fatty acids. Tellez Carmona José Manuel neurons. These synthetic fats replace the natural DHA in the membrane, which affects the electrical activity of the neuron. Unfortunately, our ingestion of trans fatty acids starts in infancy. A Canadian study showed that an average of 7.2% of the total fatty acids of human breast milk consisted of trans fatty acids which originated from the consumption of partially hydrogenated vegetable oils by the mothers. 30 WHAT ARE OMEGA -3 AND OMEGA-6 FATTY ACIDS? HOMEWORK: INDIVIDUAL! SEARCH ABOUT BOTH OMEGA ACIDS, IN AT LEAST TWO DIFFERENT WEBSITES (OBVIOUSLY WiTHOUT in the next website http://www.clo3.com/home.php Search for function Key benefits of omega 3 Why are they so necessary for human diet Tellez Carmona José Manuel LOOKING FOR IN rincondelvago, wikipedia, monografias, etc. You may look for Tridimensional shape DELIVERY FORM: VIA EMAIL TO manueltllz@gmail.com 31 Since water is also a polar molecule the polar end of the phospholipid is "attracted" to the + ends of the water molecules. It is said to be "hydrophillic" (or water loving). While the neutral end of the phospholipid molecule is nonpolar, i.e. is repelled by the "polar" water molecules, it is said to be "hydrophobic" (water fearing). PHOSPHOLIPIDS These molecules are structurally similar to the triglycerides, but they differ in one important respect. Triglycerides have 3 fatty acid chains, but the phospholipids have only 2 fatty acid chains and one phosphate (-) group. The negatively charged phosphate group (and its various end groups) cause this end of the molecule to form a "polar" covalent bond with glycerol. That is this end of the phospholipid molecule is "polar" while the fatty acid chain is "non-polar". Therefore one end of the molecule is charged (-), i.e. polar and the other end of the molecule is not charged (neutral), i.e. non-polar. Tellez Carmona José Manuel 32 T H I S D U E L N AT U R E O F T H E PHOSPHOLIPID MOLECULE MAKES I T V E RY U S E F U L A S A C O M P O N E N T O F C E L L M E M B R A N E S. Tellez Carmona José Manuel 33 AMINOACIDS, PEPTIDES AND PROTEINS Tellez Carmona José Manuel 34 PROTEINS These are very large 3 dimensional macromolecules. They are very important as structural molecules in the cell, as energy sources, and most importantly as "enzymes", (protein catalysts which speed up chemical reactions in the cell without the need for high temperature or drastic pH changes). Function Structure Motion Defense Almacenamiento Signals Catalysis Main protein functions Example Colagen in skin, keratine in hair, nails and horns Actine and miosine in muscles Antibodies in blood stream Zeatine in cornpops Growth hormone in blood stream Enzimes: they catalize almost every chemical reaction within cells, DNA polimerase (produces DNA); pepsine (digers proteins); amilase (digers carbohydrates); ATP synthetase (produces ATP) Tellez Carmona José Manuel Proteins are often called "polypeptides" because they are made of long chains of building blocks called "amino acids" 35 STRUCTURE OF SOME AMINO ACIDS - R groups can be any of 20 different forms giving 20 naturally occurring amino acids (in living things) Tellez Carmona José Manuel 36 STRUCTURE OF PROTEINS Primary Structure (or primary level of organization) Definition. "The sequence of amino acids in the polypeptide chain.“ Amino acids are bound together with a "peptide" bond. Tellez Carmona José Manuel 37 S E C O N DA RY L E V E L O F O R G A N I Z A T I O N O F P O LY P E P T I D E S There are two types of secondary structure in proteins, the α helix and the β pleated sheet. The attraction of the R groups within the same chain can cause the chain to twist into a "right handed" coil. This " α helix" is held together by hydrogen bonds between the hydrogen and oxygen atoms of the amino acid backbone (amino groups and carboxyl groups). Such "Intrachain Hydrogen Bonding" Keratin is a structural protein found in hair and nails, skin, and tortoise shells. The aHelix nature of wool is what makes it shrink. often predominate in "globular proteins". Tellez Carmona José Manuel 38 Another form of secondary structure the β pleated sheet, is caused by hydrogen bonding between the hydrogen atoms (amino group) and the oxygen atoms (carboxyl group) of amino acids on two chains (or more) lying side-by-side. The β pleated sheet structure is often found in many structural proteins, such as "Fibroin", the protein in spider webs. Tellez Carmona José Manuel 39 THE TERTIARY STRUCTURE OF PROTEINS When "proline", an oddly shaped amino acid occurs in the polypeptide chain a "kink" in the ahelix develops. Kinks can also be caused by repulsive forces between adjacent charged R groups. These kinks create a 3 dimensional chain arrangement, ie. the "Tertiary" Structure This 3 dimensional shape is also held together by weak hydrogen bonds but also by much stronger "disulfide" bonds between two amino acids of cystine ("covalent") disulfide "bridges" (linkages) cystine -- s -- s -- cystine Tellez Carmona José Manuel 40 QUATERNARY STRUCTURE OF PROTEINS This last level of organization is simply taking 2 or more 3 dimensional (tertiary proteins) and sticking them together to form a larger protein. Many enzymes and transport proteins are made of two or more parts. Tellez Carmona José Manuel 41 STRUCTURE OF PROTEINS Tellez Carmona José Manuel 42 DENATURE Proteins when heated can unfold or "Denature". This loss of three dimensional shape will usually be accompanied by a loss of the proteins function. If the denatured protein is allowed to cool it will usually refold back into it’s original conformation. Tellez Carmona José Manuel 43 NUCLEIC ACIDS These macromolecules include the Ribonucleic Acids (RNA's) and the Deoxyribonucleic Acids (DNA's). They are also long chain macromolecules. The repeating subunits (building blocks) of these molecules are called "nucleotides". Nucleotides have three parts, a sugar (usually the six carbon sugar ribose or deoxyribose), a phosphate group (P04) and a base (which contains nitrogen). Tellez Carmona José Manuel 44 BASIC STRUCTURE Nucleic acids form long chains by linking the phosphate groups to the sugars. The nitrogen bases stick out to the side. When DNA is formed there are two chains of nucleotides, each of which tends to coil around the other forming the so called "double helix". The two strands of DNA are said to form the "DNA molecule". Note: that one strand runs in one "direction" and the other strand runs in the opposite "direction". Tellez Carmona José Manuel 45 Some differences between each nucleic acid Deoxyribonucleic acid (DNA) is The DNA double helix. composed of deoxyribose sugar and four nitrogen bases, Complementary base paired, as follows; Adenine = = = Thymine Guanine = = = Cytosine RNA differs from DNA in that there is only one strand, and RNA uses ribose as its sugar, and RNA substitutes Uracil for Thymine. Adenine - Uracil Tellez Carmona José Manuel Guanine - Cytosine 46 Tellez Carmona José Manuel 47